Counting All the Carbon

Last Thursday, an editorial in the Wall St. Journal referred to a paper in the latest issue of Science entitled,&nbsp"Fixing a Critical Climate Accounting Error", which concludes that the manner in which the greenhouse gas impacts of biofuels are currently assessed fails to account for significant emissions that occur outside the envelope normally drawn around an ethanol or biodiesel plant and the farms that supply it with feedstock. And if that omission weren't glaring enough, I ran across another instance in which regulators appear to be turning a blind eye to the full impact of another popular option for addressing climate change, electric vehicles.

As we prepare to re-orient our entire
economy around the restrictions embodied in pending climate
legislation, it is essential that we account for all of the emissions
involved in a consistent way, and on a scale matching the global
environmental problem we're trying to solve. This is crucial to
making real progress on reducing emissions, rather than just making
us all feel good about what we are doing.
When the emailed table of contents for
the October 23 issue of Science showed up in my inbox last Friday, I
spotted the name of Timothy Searchinger of Princeton University as
lead author of the paper cited by the Journal today. Dr. Searchinger
was also the lead author of an earlier paper in Science that I
highlighted last February, when the debate concerning the global
land-use implications of corn ethanol was just getting underway. Dr.
Searchinger's collaborators on the new paper are an impressive bunch,
including Dr. Dan Kammen, the director of the Renewable and
Appropriate Energy Laboratory at U.C. Berkeley.

The report provides further evidence
that it's no longer appropriate to assume that just because the
carbon embodied in biofuels such as ethanol originated in green
plants that absorbed it from the atmosphere, they must therefore be
"carbon neutral"--other than the emissions from fossil
fuels used in the cultivation, harvesting and transportation of the
crops from which they are produced, along with the energy used in
their processing. Additional emissions apparently result from the
global displacement of the crops turned into energy here, and in some
cases those emissions are on a similar order of magnitude to the
direct emissions from the combustion of the biofuels--combustion that
has gotten a free pass until now.

This is a highly inconvenient result
for those engaged in the production of biofuels from food crops, on
two levels. First, it puts the climate change justification for the
subsidies and mandates responsible for the rapid ramp-up of
conventional biofuel production in question. Second, the source of
this doubt is no less than one of the same scientific journals in
which so much of the peer-reviewed science contributing to the
oft-cited scientific consensus on climate change has appeared, and
subject to the same level of scientific scrutiny. Casting doubt on
the source of this unwelcome message thus risks casting doubt on the
entire edifice upon which the current, much-expanded biofuel endeavor
rests.

Let's be clear that I don't blame the
biofuel industry for promoting a product that many thought would
help, but may ultimately turn out to do little or nothing to reduce
the greenhouse gas emissions implicated in climate change, any more
than we should blame the producers and consumers of fossil fuels for
their contribution to the accumulation of those gases before the
current consensus on climate change emerged. (I confess that I regard
attempts to portray that consensus as having existed as long as 40
years ago as the worst kind of revisionism, since the creation of the
consensus depended not on a few key insights, which might have turned
out to be wrong, but on mounting evidence from the steady
accumulation of peer-reviewed research during that interval.)

Having said that, I have a much harder
time understanding the inclusion of an equally serious--and
apparently entirely conscious--omission in the new automotive fuel
economy and emissions standards jointly developed by the
Environmental Protection Agency and the Department of Transportation.
I had occasion to browse through the agencies' proposed text and was startled to see that for
purposes of calculating carmakers' fleet CO2 emission averages, it
assumes that electric vehicles (EVs) and the electric usage of
plug-in hybrids (PHEVs) have zero lifecycle emissions. Not only that,
but the proposed regulation would count each EV as if it replaced two
other emitting cars: thus, zero GHG impact not once but twice. Even
the authors admit that this is false, and here I must quote,

"EPA recognizes that for each EV
that is sold, in reality the total emissions off-set relative to the
typical gasoline or diesel powered vehicle is not zero, as there is a
corresponding increase in upstream CO2 emissions due to an increase
in the requirements for electric utility generation. However, for the
time frame of this proposed rule, EPA is also interested in promoting
very advanced technologies such as EVs which offer the future promise
of significant reductions in GHG emissions, in particular when
coupled with a broader context which would include reductions from
the electricity generation. For the California Paley 1 program,
California assigned EVs a CO2 performance value of 130 g/mile, which
was intended to represent the average CO2 emissions required to
charge an EV using representative CO2 values for the California
electric utility grid."

But while I appreciate the agencies'
rationalization that EVs and PHEVs might be counted as having zero
emissions on a purely temporary basis in order to provide incentives
for carmakers to accelerate their introduction, I'm also painfully
aware that other such "temporary" measures have persisted
long after the original justification for them had become
obsolete--and here I can't help but think of the ethanol blending
credit that is now in its 31st year.

Why do these loopholes in the way we
tally greenhouse gas emissions matter enough for me to hammer away at
them like this? Consider the proposed vehicle rules. By ignoring
emissions that occur outside these vehicles, the government is
discouraging carmakers from using less exotic technologies that might
actually deliver comparable savings of fuel and emissions sooner, and
at a lower cost to taxpayers and consumers. A conventional Toyota
Prius hybrid running on gasoline emits only 10% more grams of CO2 per
mile than California claims for an EV powered by its
greener-than-average state electricity mix. Since the same number of
batteries could equip many more Prius-type hybrids, at a much lower
cost per car than for a full EV, the benefits of rushing EVs into
production seem much less compelling at this point, particularly when
the government is also subsidizing the purchasers of EVs and PHEVs to
the tune of many thousands of dollars per car. That will amount to
billions of dollars of extra subsidies for an incremental emissions
benefit that might just be negative for an EV recharged using
coal-fired power.

"Start as you mean to go on,"
goes the old saying. We know that whatever their energy security
benefits and general hi-tech niftiness, EVs are not zero-emission
vehicles, just as we now understand that it is likely that burning
corn ethanol releases roughly the same level of greenhouse gases as
the gasoline it is intended to replace. If cap & trade bills such
as Waxman-Markey and Kerry-Boxer are to have any integrity as tools
for achieving genuine reductions in the global greenhouse gas
emissions behind global climate change, then we must count all the
emissions from all sources, no matter how politically unpalatable
that may be. EPA and DOT might do well to heed this advice, too,
before establishing a new, impossible-to-revoke entitlement for the
manufacturers of electric vehicles.